Description of Adults of Acentrella nadineae McCafferty, Waltz & Webb, 2009 (Baetidae: Ephemeroptera) with notes on rearing and madicolous behavior of nymphs

Acentrella nadineae McCafferty, Waltz, & Webb, 2009 is broadly distributed in cool, clean, swift rocky streams across parts of the southeast, northeast, and midwestern United States, but currently its adult stages are unknown. The difficulty associated with successfully rearing nymphs of Acentrella species is mostly responsible for our lack of knowledge of adult life stages. New field observations of A. nadineae nymphs from the Hubbard River, Massachusetts, USA were used to modify an already successful rearing system for baetid nymphs to obtain a reared series of male and female imagos for study. Both life stages were photographed alive and are described herein for the first time. In addition, details of the modified rearing system and notes on the unusual madicolous behavior of near final instar nymphs are presented.